1. Field of the Invention
The present invention relates to network communications and more particularly to mechanisms for managing and controlling the delivery of web content (e.g., web pages, objects, files, applications, etc.)
2. Description of Related Art
In recent years, the Internet and the world wide web have become ubiquitous. The sheer volume of information and services available at any time via the Internet is astounding. As such, users often turn to the Internet to communicate with others, to receive current news reports, to shop, to be entertained, and for assorted other reasons.
As its name implies, the Internet is a network of computer networks. The world wide web is, in turn, an application that runs on the Internet, powered by web servers and web browsers. A web server stores or has access to “web pages” made up of various objects (e.g., text, graphics, audio, video or other media and logic) and can send the pages to web browsers that access the server via hypertext transfer protocol (HTTP) or another agreed protocol.
A web page is usually defined by a set of markup language, such as hypertext markup language (HTML), wireless markup language (WML), handheld device markup language (HTML), extensible hypertext markup language (XHTML) or compact HTML (cHTML) for instance. The markup language typically specifies text to be displayed and includes tags that direct the browser to carry out various functions. For instance, a tag can direct the browser to display text in a particular manner. Or a tag can direct the browser to request and load other objects, such as images or sound files, to be presented as part of the web page. Or as another example, a tag can direct the browser to display a hyperlink that points to another web page or object (or generally referencing any other web content).
(Note that markup language could take other forms as well. As one other example, for instance, a markup language such as voice extensible markup language (VXML) could include voice-tags that direct a browser to play out speech messages to a user. In that event, the client station might be a voice command platform with which a user communicates via a telephone link. Still other examples are also possible.)
A user operating a web browser on a client station can direct the web browser to navigate to a particular web page or to load other web content. To do so, the user may select or enter into the browser a universal resource identifier (URI), typically a universal resource locator (URL), which points to a host web server, usually by a domain name, and identifies the requested content, usually by a path and filename. In response, the browser will then generate and send to the web server an HTTP “GET” request message, which indicates the URI. When the server receives the GET request, if the requested content is available, the server will then respond by sending to the browser an HTTP “200 OK” response message that includes the requested content. And when the browser receives the HTTP response, the browser will then present the content to the user.
As is well known, Internet communications occur through a defined set of protocol layers, including an application layer, a transport layer, a network layer and a physical layer. Applications, such as a web browser and a web server, communicate with each other according to an application layer protocol, such as HTTP. And those communications are then arranged as data packets, which are passed between the applications according to a transport layer protocol such as TCP and between network nodes according to the network layer IP protocol. Each packet typically bears a TCP/IP header, which indicates source and destination IP addresses as well as source and destination TCP ports associated with the respective applications.
In order for a web client to engage in HTTP communication with a web server, the client and server will first establish a TCP “socket” or “connection” between each other. The client then sends an HTTP GET request in the TCP socket, typically through one or more routers, switches and/or proxies, to the IP address of the server. And the server responds by sending a 200 OK response in the TCP socket to the IP address of the client.
Alternatively, the web client may open up a first TCP socket with a designated proxy server, an the proxy may open up a second TCP socket with the web server. The web client may then send an HTTP GET request in the first TCP socket to the proxy, and the proxy may then send the HTTP GET request in the second TCP socket to the IP address of the web server. In turn, the web server may send a 200 OK response in the second TCP socket to the proxy, and the proxy may then send the 200 OK response in the first TCP socket to the IP address of the web client.